This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/556,158 filed Mar. 25, 2004, the complete disclosure of which is hereby expressly incorporated by reference.
The present invention pertains to a multifunctional seal that provides both seal and leak detection functionality. Redundant sealing is provided to enable the detection of leak progression of fluids in either gas or liquid phase. Leak progression detection is the detection of a propagating leak, which may be detected prior to leakage outside the sealed containment structure. Some examples of use include seals in containment and transfer systems having hazardous or environmentally damaging fluids, seals for mechanical devices having refrigerant, coolant, lubricating, or fuel fluids, and seals for structure that provides separation of dissimilar material phase, environmental, or energy state.
Fluid seals are made of a variety of materials and have a multitude of design configurations that include, but are not limited to, (i) a circular conformable elastomer O-ring seated in a channel (gland) of a metallic or plastic fitting, (ii) circular washer made of soft conformable metallic or plastic material, (iii) flat gasket of various flat pattern made with conformable fibrous, cellulous, particulate, or polymeric material, (iv) circular compression fittings with off-set tapered mating surfaces, (v) circular flared fittings with conformable flared tubings, and (vi) circular threaded pipe fittings with off-set tapers, etc.
It is known that sealing using conformable materials is achieved when such material is placed between relatively rigid mating surfaces and that sealing occurs when the material displaces to conform to and fill the space between the mating surfaces.
It is also known that sealing of relatively rigid mating surfaces is achieved when such surfaces are in full or partial and often tight contact. Examples of such sealing are compression fittings and threaded pipefittings that often have tapered mating surfaces that are offset to create tight contact during rotational tightening.
Presently, leak detection is achieved using a multitude of devices that are external and separate from the fluid containment structure and seal. Such devices include, but may not be limited to: (i) stationary chemical detection alarms, (ii) handheld portable chemical detection sensors, and (iii) handheld portable sonic emission detectors. Other means for leak detection include the use of foaming agents (soap) and dye that provide visual identification of a leak.
It is also known that leaks may be identified through the use of pressure sensors that measure fluid pressure within the containment system. Such systems typically measure bulk fluid pressure using a single pressure sensing device. Other means for direct indication of a leak include the use of temperature sensors that measure fluid temperature within the containment system. Such systems typically measure localized temperature at a specific location within the system using a single temperature sensing device. Fluid leakage can be identified by a corresponding increase in temperature readings.
Typical leak detect methods and devices identify leaks after leakage has occurred outside the fluid containment structure.
A typical fluid containment structure provides a single containment wall without redundancy in containment structure.
Current fluid seals are configured and sized to provide a single seal barrier without sealing redundancy.